Western White Pine
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208466929
2008-04-27T05:09:56Z
DHN-bot
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robot Adding: [[vi:Thông trắng miền tây]]
{{Taxobox
| name = Western White Pine
| status = LR/lc
| image = Pinus monticola0.jpg
| image_width = 240px
| image_caption = Cones and foliage of Western White Pine
| regnum = [[Plant]]ae
| divisio = [[Pinophyta]]
| classis = [[Pinophyta|Pinopsida]]
| ordo = [[Pinales]]
| familia = [[Pinaceae]]
| genus = ''[[Pine|Pinus]]''
| subgenus = ''[[Pinus classification|Strobus]]''
| species = '''''P. monticola'''''
| binomial = ''Pinus monticola''
| binomial_authority = [[David Douglas|Douglas]] ex [[D. Don]]
}}
'''Western White Pine''' (''Pinus monticola''; family [[Pinaceae]]) is a species of [[pine]] that occurs in the mountains of the western [[United States]] and [[Canada]], specifically the [[Sierra Nevada (U.S.)|Sierra Nevada]], the [[Cascade Range]], the [[Coast Range]], and the northern [[Rocky Mountains]]. The tree extends down to sea level in many areas, particularly in Oregon and Washington. It is the [[state tree]] of [[Idaho]].
[[Image:Pinus monticola1.jpg|thumb|left|Mature trees growing in a mixed stand, some showing dieback due to Blister Rust]]
Western White Pine is a large [[tree]], regularly growing to 30-50 m and exceptionally up to 70 m tall. It is a member of the [[Pinus classification|white pine]] group, ''[[Pinus]]'' subgenus ''[[Strobus]]'', and like all members of that group, the leaves ('needles') are in fascicles (bundles) of five, with a deciduous sheath. The needles are finely serrated, and 5-13 cm long. The cones are long and slender, 12-32 cm long and 3-4 cm broad (closed), opening to 5-8 cm broad; the scales are thin and flexible. The seeds are small, 4-7 mm long, and have a long slender wing 15-22 mm long.
It is related to [[Eastern White Pine]] (''Pinus strobus''), differing from it in having larger cones, slightly longer-lasting leaves (2-3 years, rather than 1.5-2 years) with more prominent [[stoma]]tal bands, and a somewhat denser and narrower habit. The branches are borne in regular whorls, produced at the rate of one a year; this is pronounced in narrow, stand-grown trees, while open specimens may have a more rounded form with wide-reaching limbs. It is widely grown as an [[ornamental tree]], but has been heavily logged throughout much of its range in the past.
[[Image:Westernwhitepinetwisty.jpg|thumb|left|Western white pine growing in Portland, Oregon]]
It has been seriously affected by the [[Cronartium ribicola|White Pine Blister Rust]] (''Cronartium ribicola''), a fungus that was accidentally introduced from [[Europe]] in [[1909]]. The [[United States Forest Service]] estimates that 90% of the Western White Pines have been killed by the blister rust west of the [[Cascade Range|Cascades]]. Large stands have been succeeded by other pines or non-pine species. The rust has also killed much of the [[Whitebark Pine]] outside of [[California]].
Resistance to the blister rust is genetic, and due to Western White Pine's genetic variability some individuals are relatively unaffected by the rust. The US Forest Service has a program for locating and breeding rust-resistant Western White Pine and [[Sugar Pine]] (see external link below). Seedlings of these trees have been introduced into the wild. <br clear = left>
==References==
* {{IUCN2006|assessors=Conifer Specialist Group|year=1998|id=42383|title=Pinus monticola|downloaded=12 May 2006}}
*[http://www.fs.fed.us/r6/dorena/ US Forest Service Dorena Tree Improvement Center]
[[Category:Pinaceae|Pine, Western White]]
[[Category:Trees of Idaho|Pine, Western White]]
[[fr:Pin argenté]]
[[pl:Sosna zachodnia]]
[[pt:Pinus monticola]]
[[vi:Thông trắng miền tây]]
[[uk:Сосна гірська веймутова]]